Sigmund bergmann



(No Model.)

S. BERGMANN. EXTENSION EIXTUEE EOE GAS 0E LAMES.

No. 426,163. Patented Apr. 22, 1890.

WITNESSES:

' |NVENTH WLM.

/7//5 ATTORNEYS.

NTTED STATES SIGMUND BERGMANN, OF NEIV YORK,

PATENT OFFICE.

N. Y., ASSIGNOR TO TI-IE BERGMANN ELECTRIC AND GAS FIXTURE COMPANY, OF SAME PLACE. K

SPECIFICATION forming part of Letters Patent No. 426,163, dated April 22, 1890.

Application tiled September 7. 1889. Serial No. 328,309. (No model.)

To @ZZ-whom t may concern.-

Be it known that I, SIGMUND BEEGMANN, of New York,in the county and State of New Y orlz, have invented a certain new and useful Improvement in Extension-Fixtures for Gas or Lamps, of which the following is a specification.

The invention consists in the construction and novel arrangement of parts as hereinafio ter specified. lleretotore in extension-fixtures of this character where a friction-spring is employed a clutch mechanism has been em ployed. rllhis is objectionable, as it adds greatly to the cost of the iixturc, and is liable by sudden movement to break the spring and render the device useless. In my device no clutch is employed, and the block through which the tube slides has no vertical movement, and its ends bear against the ends of its chamber.

In the accompanying drawings, Figure l is a longitudinal section and partial elevation of the device embodying my invention, and Fig. 2 is a plan view with the chamber-cap removed.

Similar letters of reference design atc corresponding parts in both figures.

Referring by letter to the drawings, A designates the extension or sliding tube, intended to carry a gas-burner or lamp-holder at its lower extremity, and I3 is a 'fixed tube into which the tube A slides. The tube A is angular in cross section, and is twisted or formed with spiral ribs to engage with and rotate the block C, which has a longitudinal opening through it corresponding to the form in cross-section of the tube A.

D is a barrel secured to the lower end of the tube IS, and having a central opening for the passage of the tube A. 'lhis barrel D provides a chamber d for the block C and the flat spring c, which has one end rigidly secured to the blocl,aiid its free portion laps around the block and has a frictional bear- 45 ing against the wall of the chamber d. A cap ct removably engages, by a screw-thread or otherwise, the lower end of the barrel I), and

has an opening through which the tube A slides.

The length of the block C is such that its ends abut against the inner wall of the barrel and the inner face of the cap, so that the block has no vertical play or movement to change the tension of t-he spring.

In operation, when the tube A is drawn downward, the block C is revolved with the spring in such direction that the spring is wound so that its friction is increased on the wall of the chamber. It is evident that the tube A may be stopped and held at any desired point. In pushing the tube A upward the block C is rotated and the tension of the spring is relaxed, and the movement is quite easy.

The upper end of the tube A may be provided with any suitable packing to prevent escape of lVhat I claim as my invention, and desire to secure by Letters Patent, is-

l. In an extension-fixture, the combination,

with a fixed tube and a spiral sliding tube angular in cross-section, of a barrel on the lower end ot the xed tube, providing a chamber, a cap for said barrel, a rotary block within the chamber surrounding the sliding tube and rotated by the tube in its upward and downward movement, and a frictionspring secured to the block, substantially as specified.

2. In an extension-fixture, the combination, with the fixed tube and the sliding tube, of the barrel on the end of the ixed tube, providing a chamber, a cap for said barrel, a rotary plug surrounding and engaging with the sliding tube within the chamber, a spring secured to said plug and having a frietional bearing on the wall of the chamber, the said plug having a length equal to the length oi' the chamber, so that it has no vertical move ment, substantially as specified.

SIGMUND BERGMANN.

Vvvitnesses:

P. Il. KLEIN, Jr., CHARLES T. DUFFY. 

